z8530serial.c

IXP425的BSP代码

/* z8530Serial.c - Z8530 SCC (Serial Communications Controller) tty driver*/

/* Copyright 1984-1996 Wind River Systems, Inc. */
#include "copyright_wrs.h"

/*
modification history
--------------------
01s,14may96,dat  add intLock()/intUnlock in tyCoStartup(). spr #5971
01r,22aug95,kkk  undo 01b change
01q,03aug95,kkk  fix warnings for I960 (spr# 4177)
01p,16mar95,kvk  written, to access the data registers indirectly. 
		(MV162FX requires this)
01o,01dec92,jdi  NOMANUAL for tyCoInt(), tyCoIntRd(), tyCoIntEx(), tyCoIntWr(),
		 - SPR 1808.
01n,28oct92,caf  tweaked tyCoDevCreate() documentation.
01m,02sep92,ccc  change name from z8530Lib.c to z8530Serial.c
01l,18jul92,smb  Changed errno.h to errnoLib.h.
01k,05jun92,ccc  made board independant.  ansified.
		 renamed to z8530Lib.c.
01j,26may92,rrr  the tree shuffle
01i,21apr92,ccc  cleanup of ansi warnings.
01h,11dec91,jdi  more doc cleanup.
01g,04oct91,rrr  passed through the ansification filter
		  -changed VOID to void
		  -changed copyright notice
01f,13sep91,jdi  documentation cleanup.
01e,10aug90,dnw  added forward declarations of void functions.
01d,10jul90,gae  release 5.0 upgrade.
01e,08may90,kdl  changed baud rate to use BAUD_CLK_FREQ instead of SYS_CPU_FREQ.
01d,05mar90,dab  fixed interrupt handling in tyCoInt().
01c,20aug89,gae  changed iv68k.h to iv.h.
01b,09aug87,gae  clean up.
01a,26apr88,dfm  written, by modifying 01g of the iv24 version.
*/

/*
DESCRIPTION
This is the driver for the Z8530 SCC (Serial Communications Controller).
It uses the SCCs in asynchronous mode only.

USER-CALLABLE ROUTINES
Most of the routines in this driver are accessible only through the I/O
system.  Two routines, however, must be called directly: tyCoDrv() to
initialize the driver, and tyCoDevCreate() to create devices.

Before the driver can be used, it must be initialized by calling tyCoDrv().
This routine should be called exactly once, before any reads, writes, or
calls to tyCoDevCreate().  Normally, it is called by usrRoot() in usrConfig.c.

Before a terminal can be used, it must be created using tyCoDevCreate().
Each port to be used should have exactly one device associated with it by
calling this routine.

IOCTL FUNCTIONS
This driver responds to the same ioctl() codes as a normal tty driver; for
more information, see the manual entry for tyLib.  Available baud rates
range from 50 to 38400.

SEE ALSO
tyLib
*/

#include "vxWorks.h"
#include "iv.h"
#include "ioLib.h"
#include "iosLib.h"
#include "tyLib.h"
#include "intLib.h"
#include "errnoLib.h"
#include "drv/serial/z8530.h"

#define DEFAULT_BAUD	9600

IMPORT TY_CO_DEV tyCoDv []; /* device descriptors */

LOCAL int tyCoDrvNum;		/* driver number assigned to this driver */

/* forward declarations */

LOCAL void   tyCoStartup ();
LOCAL int    tyCoOpen ();
LOCAL STATUS tyCoIoctl ();
LOCAL void   tyCoHrdInit ();
LOCAL void   tyCoInitChannel ();
LOCAL void   tyCoResetChannel ();

/*******************************************************************************
*
* tyCoDrv - initialize the tty driver
*
* This routine initializes the serial driver, sets up interrupt vectors, and
* performs hardware initialization of the serial ports.
*
* This routine should be called exactly once, before any reads, writes, or
* calls to tyCoDevCreate().  Normally, it is called by usrRoot() in
* usrConfig.c.
*
* RETURNS: OK, or ERROR if the driver cannot be installed.
*
* SEE ALSO: tyCoDevCreate()
*/

STATUS tyCoDrv (void)

    {
    /* check if driver already installed */

    if (tyCoDrvNum > 0)
	return (OK);

    tyCoHrdInit ();

    tyCoDrvNum = iosDrvInstall (tyCoOpen, (FUNCPTR) NULL, tyCoOpen,
				(FUNCPTR) NULL, tyRead, tyWrite, tyCoIoctl);

    return (tyCoDrvNum == ERROR ? ERROR : OK);
    }

/*******************************************************************************
*
* tyCoDevCreate - create a device for an on-board serial port
*
* This routine creates a device on a specified serial port.  Each port
* to be used should have exactly one device associated with it by calling
* this routine.
*
* For instance, to create the device "/tyCo/0", with buffer sizes of 512 bytes,
* the proper call would be:
* .CS
*     tyCoDevCreate ("/tyCo/0", 0, 512, 512);
* .CE
*
* RETURNS: OK, or ERROR if the driver is not installed, the channel is
* invalid, or the device already exists.
*
* SEE ALSO: tyCoDrv()
*/

STATUS tyCoDevCreate
    (
    char *      name,           /* name to use for this device      */
    FAST int    channel,        /* physical channel for this device */
    int         rdBufSize,      /* read buffer size, in bytes       */
    int         wrtBufSize      /* write buffer size, in bytes      */
    )
    {
    FAST TY_CO_DEV *pTyCoDv;

    if (tyCoDrvNum <= 0)
	{
	errnoSet (S_ioLib_NO_DRIVER);
	return (ERROR);
	}

    /* if this doesn't represent a valid channel, don't do it */

    if (channel < 0 || channel >= tyCoDv [0].numChannels)
	return (ERROR);

    pTyCoDv = &tyCoDv [channel];

    /* if there is a device already on this channel, don't do it */

    if (pTyCoDv->created)
    return (ERROR);

    /* initialize the ty descriptor */

    if (tyDevInit (&pTyCoDv->tyDev, rdBufSize, wrtBufSize,
		   (FUNCPTR) tyCoStartup) != OK)
	{
	return (ERROR);
	}
    
    /* initialize the channel hardware */

    tyCoInitChannel (channel);

    /* mark the device as created, and add the device to the I/O system */
    
    pTyCoDv->created = TRUE;

    return (iosDevAdd (&pTyCoDv->tyDev.devHdr, name, tyCoDrvNum));
    }

/*******************************************************************************
*
* tyCoHrdInit - initialize the USART
*/

LOCAL void tyCoHrdInit (void)

    {
    FAST int   oldlevel;	/* current interrupt level mask */
    int        ix;
    
    oldlevel = intLock ();	/* disable interrupts during init */
    
    for (ix=0; ix < tyCoDv [0].numChannels; ix++)
    tyCoResetChannel (ix);	/* reset channel */
    
    intUnlock (oldlevel);
    }
    
/********************************************************************************
* tyCoResetChannel - reset a single channel
*/

LOCAL void tyCoResetChannel
    (
    int channel
    )
    {
    volatile char *cr = tyCoDv [channel].cr;        /* SCC control reg adr */
    int delay;
    int zero = 0;

    *cr = zero;		/* SCC_WR0_NULL_CODE sync the state machine */
    *cr = zero;		/* SCC_WR0_NULL_CODE sync the state machine */
    *cr = SCC_WR0_ERR_RST;
    *cr = SCC_WR0_RST_INT;

    *cr = SCC_WR0_SEL_WR9;      /* write register 9 - master int ctrl */
    
    *cr = ((channel % 2) == 0) ?
    SCC_WR9_CH_A_RST :      /* reset channel A */
    SCC_WR9_CH_B_RST;       /* reset channel B */

    for (delay = 0; delay < 1000; delay++)
    ;     /* spin wheels for a moment */
    }

/*******************************************************************************
*
* tyCoInitChannel - initialize a single channel
*/

LOCAL void tyCoInitChannel
    (
    int channel
    )
    {
    FAST TY_CO_DEV *pTyCoDv = &tyCoDv [channel];
    volatile char  *cr = pTyCoDv->cr;	/* SCC control reg adr */
    FAST int   	    baudConstant;
    FAST int        oldlevel;		/* current interrupt level mask */
    int	            zero = 0;

    oldlevel = intLock ();		/* disable interrupts during init */

    /* initialize registers */

    *cr = SCC_WR0_SEL_WR4;              /* write reg 4 - misc parms and modes */
    *cr = SCC_WR4_1_STOP | SCC_WR4_16_CLOCK;

    *cr = SCC_WR0_SEL_WR1;
    *cr = SCC_WR1_INT_ALL_RX | SCC_WR1_TX_INT_EN;

    *cr = SCC_WR0_SEL_WR3;		/* write reg 3 - receive params */
    *cr = SCC_WR3_RX_8_BITS;

    *cr = SCC_WR0_SEL_WR5;		/* tx params */
    *cr = SCC_WR5_TX_8_BITS | SCC_WR5_DTR | SCC_WR5_RTS;

    *cr = SCC_WR0_SEL_WR10;		/* misc tx/rx control */
    *cr = zero;				/* clear sync, loop, poll */

    *cr = SCC_WR0_SEL_WR11;		/* clock mode */
    *cr = pTyCoDv->clockModeWR11;

    *cr = SCC_WR0_SEL_WR15;		/* external/status interrupt cntrl */
    *cr = zero;

    /* Calculate the baud rate constant for the default baud rate
     * from the input clock frequency.  This assumes that the
     * divide-by-16 bit is set (done in WR4 above).
     */

    baudConstant = ((pTyCoDv->baudFreq / 32) / DEFAULT_BAUD) - 2;

    *cr = SCC_WR0_SEL_WR12;		/* LSB of baud constant */
    *cr = (char) baudConstant;		/* write LSB */
    *cr = SCC_WR0_SEL_WR13;		/* MSB of baud constant */
    *cr = (char) (baudConstant >> 8);	/* write MSB */

    *cr = SCC_WR0_SEL_WR14;		/* misc control bits */
    *cr = pTyCoDv->clockModeWR14;

    *cr = SCC_WR0_SEL_WR15;		/* external/status interrupt control */
    *cr = zero;

    *cr = SCC_WR0_RST_INT;		/* reset external interrupts */
    *cr = SCC_WR0_ERR_RST;		/* reset errors */

    *cr = SCC_WR0_SEL_WR3;		/* write reg 3 - receive params */